1. Field of the Invention
This invention generally relates to integrated circuit (IC) memory fabrication and, more particularly, to a PrxCa1−xMnO3 (PCMO) memory film and associated film process.
2. Description of the Related Art
In order to meet the requirements of low power, low operation voltage, high-speed, and high-density memory applications, electrically alterable resistors are being investigated that can be fabricated from PCMO. Metalorganic chemical vapor deposition (MOCVD), sputtering, laser ablation, and metalorganic deposition (MOD) methods can be used, along with appropriate surface treatments, to deposit PCMO on various substrates. The different deposition methods are being investigated to address the control of specific interfacial properties of the PCMO, such as lattice mismatch, trapped charge density, as well as bulk properties such as grain size and film. Reversible and non-volatile resistance changes in the PCMO film are desirable using either bipolar or unipolar pulsed biasing. Therefore, an understanding the relationship between memory characteristics and PCMO thin film material structure is sought. PCMO also exhibits colossal magnetoresistive (CMR) properties. These are also strongly affected by thin film crystal structure. An understanding of the relationship between crystal structure and an electrically alterable resistance suitable for RRAM devices is desired.
It would be advantageous if the memory resistance characteristics of a PCMO film could be controlled and optimized by the judicious choice of crystallization and orientation of PCMO thin films.